When the smoke literally cleared on Monday, investigators had a huge problem and nearly no leads. No individual or organization claimed responsibility for the bombings that killed three and wounded more than 180. So they took a big leap: They copped to how little they knew, and embraced the wisdom of The Crowd.

Hiding in plain sight was an ocean of data, from torrents of photography to cell-tower information to locals’ memories, waiting to be exploited. Police, FBI, and the other investigators opted to let spectator surveillance supplement and augment their own. When they called for that imagery, locals flooded it in. They spoke to the public frequently, both in person and especially on Twitter. All that represented a modern twist on the age-old law enforcement maxim that the public’s eyes and ears are crucial investigative assets, as the Internet rapidly compressed the time it took for tips to arrive and get analyzed.

The essence of the 1929 plan was the division of the region into Slab City—the high-rises of Manhattan—and Spread City, the suburbs that surround the city center. This was enabled by the building of a set of highways that made it possible to travel to and from the city, or comfortably around it if you were traveling elsewhere. The guiding idea was to concentrate high-end activities in the city center—finance and other fancy service businesses that could afford high rents—and move the noxious stuff out to Jersey.

The city would be reconfigured in line with this rough hierarchy: (1) financial business, (2) fancy retail, (3) fancy residential, (4) inferior retail, (5) wholesalers and, at the bottom of the list, (6) industry and working-class housing. The ultimate goal was to turn the city into one of the peaks at the commanding heights of global economic activity: finance, senior management and media.

As Fitch would later argue in The Assassination of New York, the deindustrialization of the city—more than 700,000 manufacturing jobs, two-thirds of the total, disappeared between 1950 and 1990, a period when national factory employment rose by more than a third—wasn’t merely the product of “outside forces” like globalization and technological change. It was planned, via the influence of the RPA and other entities like the Real Estate Board of New York on the city planning apparatus. Instead of protecting manufacturing as a valuable resource using zoning and tax breaks, exactly the opposite tack was taken: zoning changes and tax breaks designed to squeeze the little factories out and replace them in accordance with the six-part hierarchy listed above.

Forced migration from environmental causes—be they sudden onset, like a typhoon, or slow onset, like a drought—does not a refugee make. There is simply no such thing as an “environmental refugee” because to be a refugee, one must face persecution. Even if you were to argue that climate change is a form of indirect persecution of the world’s most vulnerable by the world’s richest and most over-consumptive countries (like the U.S. or China), who pump enough CO2 into the global sky to change weather across the globe, according to McAdam, you’d have to prove that the persecution was on account of the impacted person’s race, religion, political opinion, nationality, or social group. That is to say, you’d have to make the case for intent. And you’d be hard-pressed to do so.

But we have to start somewhere, because the predictions are astonishing. As Alice Thomas, of the Bacon Center for the Study of Climate Displacement at Refugees International, says, “If we don’t act now to put policies in place, we’re going to really limit our ability to act in the future.”

As the world heats up and crowds with more humans who are hungry, thirsty, and consuming fossil fuels, more and more people are finding their homes unlivable: nearly one million Somalis displaced (many to Kenya) during the 2011 famine; 600,000 displaced by flooding in Bangladesh this past July; the entire population of islands like Tuvalu (11,000) and Kiribati (over 100,000) threatened with forced departure as their islands sink slowly but surely into the sea. Given that climate change has brought us a new set of international conditions that impact the way people live (and if they can live at all) on a very large scale, the U.N. recognizes that there is a dire need to plan for protection of current and future climate migrants.